This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. In this application we plan to investigate the pathophysiology and pathoanatomy in genetically determined and idiopathic Parkinson's disease (PD) in different stages of PD (asymptomatic and symptomatic stage). We propose the following aims: First, using positron emission tomography (PET), to measure regional cerebral dopamine concentration and glucose metabolism in patients with genetically determined (LRRK2 mutation carriers) and idiopathic PD and normal volunteers in order to determine the specific abnormalities of brain metabolism in PD. Second, using magnetic-resonance-imaging (MRI), to investigate structural patterns in patients with genetically determined (LRRK2 mutation carriers) and idiopathic PD and normal volunteers in order to determine the specific abnormalities of brain structure in PD.